Grinding wheel and means for mounting and driving the same



'March 19,

J. E. SANSIG GRINDING WHEEL AND MEANS FOR MOUNTING AND DRIVING THE SAME Hai.

Filed March 14, 1956 GRINDING WHEEL AMB- MEANS FOR MGUNT- ING AND DRWEIM THE SAME Joseph E. Sansig, Stahlstown, Pa, assignor to Simonds Abrasive Company, Philadelphia, Fa, a corporation of Pennsylvania Application'March 14, W56, Serial No. 571,440

8 Claims. (Cl. 51-168) This invention relates to grinding wheels and is con cerned primarily with mechanical details of the mounting and driving of such wheels. it was conceived and developed as a solution to problems encountered in the mounting and use of heavy duty grinding wheels known as snagging wheels and designed. for use at high. speeds, but may of course also be used with other wheels presenting similar problems.

Wheels of this type are ordinarily secured in place between opposed clamping plates or flanges, and driven by rotation of a shaft mounted within. these plates and secured to one of them. The grinding wheel. proper is supported on an annular flange extending axially from one of these plates into the central bore of the wheel, but the driving force is derived through the clamping pressure applied laterally to force. the plates against opposite faces of the wheel. it is considered undesirable, in the mounting of the abrasive wheel proper upon. the mounting and driving structure so provided, to secure the wheel by a key or the like against slippage, since this is regarded as unsafe in view of the heavy and concentrated load. so applied. It has been recognized that the alternative method of mounting and. driving actually used was objectionable because of slippage and phenomena of chatter and vibration which reduced the efiectiveness. of the grinding markedly. However, these, undesired consequences were accepted as lesser evils than those which would result from keying the rotating parts together.

A primary object of the presentinventionhas been to provide an improved mounting by which slippage is entirely avoided, and chatter and vibration also substantially eliminated, while avoiding the undesirable consequences of use of keys and key-ways.

A further object of the invention has been to eliminate the wear upon the operating parts resulting. from slippage of the grinding wheel upon its mounting, and thus avoid the danger and damage resulting from breakages caused by such wear.

A further object has been toteffect an economy inmanu: facture by providing a mounting which eliminates the necessity for machining certain parts to close tolerances, such as have heretofore been required.

Still further objects and advantages, and the manner in which they have been attained, will be evident from reading of the following detailed description inthe light of the attached drawing, in which:

Figure 1 is a front elevation of a grinding wheel having the features of the invention,

Figure 2 is an enlarged cross-section through the central portion of this wheel and its mounting.

Figure 3 is a detailed perspective view, illustrating a portion of the driven force of the abrasive Wheel and the complemental portion of an associated driving ring, and

Figure 4 is a partial cross-section through the grinding wheel and apparatus for casting the driving facing member against it adjacent its inner circumference.

The abrasive wheel proper may be a member composed of aluminum oxide or other abrasive particles Patent O 2,785,515 Patented Mar. 19, 1957 bonded together by a resinoi-d or other binder known in the art. This wheel is mounted concentrically about a stationary mounting shaft 11 which supports a hollow rotatable shaft 12, and this latter shaft is driven. by a pulley 13 from any suitable source of power, to drive the wheel 10.

A driving flange 14 is rigidly secured to or a part of shaft 122, and this flange M is the driving plate which transmits rotation from shaft 12 to wheel it To this end, the plate 14 is provided with a plurality of nonparallel ribs 15. While these ribs may be formed directly on the outer radial portion of the inner face of plate 1 they are preferably formed on a separate driving ring 16, which is bolted within plate 14 as by having screws 17 projecting through the plate and threaded. into ring. 16. The ribs 15 are preferably arranged in a radially exending group equally spaced about the inner faceof the ring 16.

In the mounting of the abrasive annulus Jill, it is clamped against the ring 16, and it is provided with a plurality of grooves 18 which are complemental, both. in shape and spacing,.t-o the ribs 15, being of tapering width whichis greatest at the outer face 19.

The grooves 118 are provided in. a special facing member 22, which is secured. within a circumferentially rabbeted. portion of the face of the abrasive annulus and which also has a circumferential inner axial extension 23 which serves as the central. bushing to guide and mount the abrasive annulus upon the axially extending circumferential mounting flange 24 of plate The: facing. member 2?; is preferably formed of a resilient. but substantially rigid synthetic resinous material. One such material which I have found to be satisfactory is the product sold under the trade name of Carbo- Vitrobond by the Atlas Mineral Products Co. of Mertztown, Pa... and constituting a casting composition con.- taining thiokol and free sulphur. Other materials. may be substituted in this use, however, provided they have the desired physical properties. Polystyrene. resins may, for example be used, or other facing materials. However, if a metal or other facing of great rigidity is employed, the advantages of. the invention will be partially lost due to attainment of a less flexible drive and the necessity for more accurate meshing of parts.

In the preferred form of the invention using a resinous facing, the bonding of the facing 22 to the abrasive annulus may be accomplished as illustrated schematically in Figure 4. Here the annulus lit is supported through the outer circumference of its rubbeted portion at 25 upon a casting. flange adapter 26 which is in turn mounted upon a support 27 and surrounds a casting arbor. or shaft 28. The upper face of adapter 243 is provided with ribs 29 which are similar in spacing and shape to the ribs 15 on the: ring 16. As a consequence of this combination, when the facing. material is injected or poured in molten form to fill the space at 32' and the underlying space between members It}, 26 and 28, and this material then solidifies, it provides the facing and. bushing member 22, 23, which is an integral part of the abrasive annulus through the bonding so achieved.

The. abrasive annulus 10 with its facing 22 is held clamped in contact with driving ring 16 for. drive through shaft 12 and plate 14 by an opposed clamping plate 33, and this clamping plate is positioned and held by a clamping nut 34 secured to shaft 12. It will thus be seen that the abrasive annulus with its facing member is held in intermeshed resiliently clamped relationship against the driving flange or plate 14 through the ribs 15' of driving ring 16.

The flange 24 is not relied upon for the positioning or driving of the annulus 113 and serves primarily only as a guide in assembly of the parts. From the fact that the ribs 15 are non-parallel, it will be seen that they provide the radial positioning of the abrasive annulus when brought home into complemental grooves 19, without reliance upon the flange 24 for this function. Since bushing 23 does not therefore need to fit closely upon flange 24, this eliminates the necessity for machining to close tolerances, and indeed the bushing 23 may be cast to a form which is slightly oversize at its inner circumference. In case of a relatively close fit, the pressure brought by plate 33 against opposed faces of the annulus 10 cause the inner circumference of the bushing portion 22 to be slightly distorted so that it comes into firm engagement with the outer circumference of ange 24, if this be desired. However, the extensive bearing between ribs and grooves 18 makes it unnecessary to provide a bearing surface at this location.

The fact that the facing member 22 is slightly distortable and resilient also has another important bearing on economy of manufacture and excellence of performance. Since reliance is had upon extensive contact between ribs '15 and grooves 18 to effect radial location of annulus 10 and drive thereof, it would be necessary to manufacture these parts with very close tolerances except for the-fact that the grooves 18 are capable of being distorted to a slight degree to accommodate the ribs 15. While I do not wish to be limited as to any specific theory regarding the improved results attained in practice of the invention, it is my belief that the excellent results in maintaining the grinding annulus in contact with the work and in minimizing vibration and chatter are also largely attributable to this feature.

Persons skilled in the art will realize that the invention may be refined and modified in various ways without departing from its fundamental spirit. I therefore wish it to be understood that this invention is not to be limited in interpretation except by the scope of the following claims.

I claim:

1. In a grinding wheel, the combination comprising an abrasive grinding wheel annulus, a rotary driving member mounted centrally within said annulus, a driving plate secured for rotation with said rotary driving member and having a driving face opposite a confronting face of said annulus, a resilient but substantially rigid facing member of synthetic resinous material secured against said confronting face of said annulus, and means for clamping said annulus and driving plate together with said facing member interposed therebetween and secured in driving relationship between said confronting face of said annulus and said driving face of said driving plate, the driving connection between said parts including a ribbed intermeshed driving relationship between said driving plate and said facing member comprising complemental interlocked ribs and grooves on the adjacent faces thereof extending in non-parallel directions.

2. In a grinding Wheel, the combination comprising an abrasive grinding wheel annulus, a rotary driving member mounted centrally within said annulus, a driving plate secured for rotation with said rotary driving member and having a driving face opposite a confronting face of said annulus, a resilient but substantially rigid facing member of synthetic resinous material secured against said confronting face of said annulus, and means for clamping said annulus and driving plate together with said facing member interposed therebetween and secured in driving relationship between said confronting face of said annulus and said driving face of said driving plate, the driving 4 connection between said parts including a ribbed intermeshed driving relationship between said driving plate and said facing member comprising complemental radially extending interlocked ribs and grooves on the adjacent faces thereof.

3. In a grinding wheel, the combination comprising an abrasive grinding wheel annulus, a rotary driving member mounted centrally within said annulus, a driving plate secured for rotation with said rotary driving member and having a driving face opposite a confronting face of said annulus, a resilient but substantially rigid facing member of synthetic resinous material secured against said confronting face of said annulus, and means for clamping said annulus and driving plate together with said facing member interposed therebetween and secured in driving relationship between said confronting face of said annulus and. said driving face of said driving plate, the driving connection between said parts including a ribbed intermeshed driving relationship between said driving plate and said facing member comprising complemental radially extending interlocked ribs and grooves uniformly spaced around the adjacent faces thereof.

4. In a grinding wheel, the combination comprising an abrasive grinding wheel annulus, a rotary driving member mounted centrally within said annulus, a driving plate secured for rotation with said rotary driving member and having a driving face opposite a confronting face of said annulus, a resilient but substantially rigid facing member ofsynthetic resinous material integrally bonded against said confronting face of said annulus, and means for clamping said annulus and driving plate together with said facing member interposed therebetween and secured in driving relationship between said confronting face of said annulus and said driving face of said driving plate, the driving connection between said parts including a ribbed intermeshed driving relationship between said driving plate and said facing member comp-rising complemental interlocked ribs and grooves on the adjacent faces thereof extending in non-parallel directions.

5. In a grinding wheel, the combination corn-prising an abrasive grinding wheel annulus, a rotary driving member mounted centrally within said annulus, a driving plate secured for rotation with said rotary driving member and having a driving face confronting a driven face of said annulus, a facing member interposed between. said confronting faces of said driving plate and annulus, and means or clamping said annulus and driving plate together with said facing member interposed therebetween, the driving connection between said parts including a ribbed intermeshed driving relationship between two of said interclamped parts comprising interlocked ribs and grooves on the adjacent faces thereof extending in nonparallel directions.

6. A grinding wheel and mounting and driving connection therefor as defined in claim 5, in which said driving plate includes a separate ring secured to the main body thereof and forming the portion thereof confronting a face of said annulus.

7. A grinding Wheel and mounting and driving connection as define-d in claim 6, in which said separate ring is bolted to the main body of said driving plate.

8. A grinding wheel and mounting and driving connection as defined in claim 5 in which said facing mem- .ber is formed of a resilient but substantially rigid thiokol synthetic resin.

No references cited.

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